In June, the House of Commons hosted a talk on the Muslim Brotherhood movement, and how it is spreading across the globe. Steven Merley, a former financial trader turned investigator of extremist movements, has probed the Brotherhood for over a decade. It is particularly active in Britain and according to Merley, its strategy is to "create mischief" with a heavy emphasis on Muslim victimhood including the charge that the West has been waging a war on Islam. This has been a powerful radicalising factor in young Muslims.

The Brotherhood's tactic to advance this strategy, says Merley, has been to establish a dizzying number of organisations and initiatives which create the impression of broad-based support. In reality, the sponsors are the same individuals and groups whose leaders have not changed over decades.

Just as the US Justice Department and FBI take Merley's work seriously, we should too. He is no ideologue and is as troubled by right-wing groups demonising ordinary Muslims today as he is by the Brotherhood itself.

By "ordinary" Muslims he means the vast majority who see Islam as a religious belief, rather than the political ideology usually known as "Islamism". The latter is a variant of Islam developed over 80 years ago in Egypt by the Muslim Brotherhood's founder, a teacher called Hassan al-Banna.

Disturbed by what he perceived as the corrupting influence of Western secularism on Muslims, al-Banna believed that only a return to what he saw as the original and pure form of Islam would restore the Muslim world to former glory.

Accordingly the Brotherhood adopted the slogan "The Koran is our constitution" around which all of society should be organised. To al-Banna there was no difference between religion and politics because religion was politics.

Over the decades, from this Islamist ideological trunk have sprung more radical offshoots, including al-Qaeda. For it was al-Banna who inspired the jihadist belief in elevating death over life, which arouses such incomprehension in the rest of us.

Today the original "Society of Muslim Brothers", as al-Banna called his group, has morphed into a broader movement which the Brotherhood's former "Supreme Guide" Mohamed Akef says now spans more than 70 countries. Some say that following the collapse of fascism and Communism it is fast becoming the latest — and potentially most dangerous —of history's grand political ideas. The former head of the MI6, Sir Richard Dearlove, for example, has described the Muslim Brotherhood as being "at heart, a terrorist organisation".

Let me be clear: followers of the Brotherhood in Britain are not advocating violent jihad here. They condemned the beheading in May of Drummer Lee Rigby by two Muslims on a London street in broad daylight. Their organisations have civic-sounding names; they emphasise human rights, respect for democracy and integration.

And by and large they are regarded as harmless, more pious than political with some in the bien pensant slightly in thrall to them as moderate alternatives to violent extremists. The Guardian comment pages have provided leading Brotherhood thinkers with platforms.

Yet it is Merley's contention that what the Brotherhood actually do and say has also contributed to keeping young Muslims angry. I think he is right.

Here in Britain, we cheered on the Arab Spring, which has brought the Brotherhood's parent organisation in Egypt to power. Last year, the "Freedom and Justice" party created by the Brotherhood won the presidential election. We were told there was nothing to be fearful of because since al-Banna's day, the Brotherhood had embraced pluralism and democracy. As Khairat al-Shater, an influential Brotherhood strategist, put it: "We respect the rights of all religious and political groups."

Well, not quite. Since the Muslim Brotherhood came to power in Egypt, for example, they have rejected a draft UN declaration calling for an end to "all forms of violence against women". The Brotherhood say it "contradict(s) established principles of Islam" and "undermines Islamic ethics". It does so by "granting equal rights to adulterous wives", "full rights to file legal complaints against husbands", "allowing Muslim women to marry non-Muslims" and "cancelling the need for a husband's consent in matters like travel, work or use of contraceptives".

The government of President Mohamed Morsi has also prosecuted journalists and bloggers and he tried to introduce a decree preventing judicial review of his decisions. Greeted by outrage, Morsi replaced it with a new constitution, but it didn't protect freedom of expression and religion, or end military trials.

Why should this worry us? The received wisdom among many academics and analysts in Britain and America is that the original Egyptian Brotherhood has evolved into a set of diffuse alliances among Muslim communities around the world sharing only a loosely linked ideology. "There is no reason to fear it as a menacing global web," says Professor Nathan J. Brown of George Washington University.

Really? Not according to Steven Merley. He scours the web and other sources for prime source facts and publishes them in a daily intelligence digest called "Global Muslim Brotherhood Daily Watch".

The Brotherhood movement may not operate as a rigidly disciplined, centralised Stalinist organisation like the Comintern in the Soviet era. But Merley says its global network clearly does have a structure which operates in semi-secrecy.

In Europe, the Brotherhood has established 19 organisations dealing with theology, education, political lobbying, organising conferences, publishing newsletters, and sponsoring youth events. Their umbrella organisation is the Federation of Islamic Organisations Europe (FIOE), created in 1989. Little is known about its sources of funding.

The FIOE has close links to Egypt. Its secretary general, Ayman Aly, recently moved to Cairo to become one of President Morsi's advisers. Belgian FIOE executive Bassem Hatahet has also been appointed to the Brotherhood-dominated opposition to Assad in exile, the Syrian National Council, backed by Barack Obama and David Cameron.

A key group within the FIOE is the European Council for Fatwa and Research (ECFR), whose chairman is Sheikh Yusuf Qaradawi, often referred to as the Brotherhood's spiritual leader. ECFR fatwas advise imams on what to tell Muslims in Europe about what is compatible with sharia.

The rare glimpses of ECFR proceedings do not inspire confidence that it engenders integration. A Sudanese cleric, for example, ruled that marriage without a male guardian's consent is invalid, and that adoption is haram(forbidden) because the non-biological child might see their adopted mother in a state of undress. Nor should the adopted child's rights be equal to the mother's biological child.

In Egypt, the Muslim Brotherhood's deputy chairman, Professor Mohammed Habib, has said that although the Brotherhood's foreign "entities . . . work in different circumstances and different contexts", they all "have the same ideology, principle and objectives". So what exactly are those objectives?

By far the single most influential figure over the global Muslim Brotherhood has been Sheikh Qaradawi. Now 86, the cleric has described its objective as ensuring that "Islam will come back to Europe for the third time", having been expelled twice. This "conquest", says Qaradawi, will not be "through the sword, but through Da'wa", a form of proselytising; the FIOE has been established to start that "conquest". And after Europe? "We will conquer America," he says. It's a message Qaradawi has repeated since the FIOE was set up.

In 2005 I talked all this through with a British Brotherhood follower, Anas Altikriti, founder of a lobby and research group named after Cordoba, capital of the last Islamic Caliphate to have a toehold in Europe nearly 1,000 years ago. He admits to having been "extremely closely linked to the Muslim Brotherhood" when he lived in the Arab Emirates, and today acknowledges that in London he also belongs to a "very similar school of thought". So I asked him if he thought that his spiritual leader's prophecy was perhaps a bit fantastical?

Altikriti: No, I believe in it because that is the prophecy of the Prophet. It's not an invention of Sheikh Qaradawi. The Prophet Muhammad, in a famous authentic Hadith, promised his companions that at a great time of strife —which was miraculous in itself — that Constantinople would be conquered and Rome . . .

Ware: So it's an aim to convert all those people . . .

Altikriti: Who said it was an aim? I said it was a prophecy.

Ware: I thought it was an imperative.

Altikriti: The only obligation that I have, the only obligation I have is what I call Da'wa.

Before arriving in Britain to set up the Muslim Association of Britain in 1997 (which became part of the FIOE), a senior Egyptian Brother Kamal Helbawi said: "This religion that is Islam shall govern the whole universe, the Islamic civilisation should rule and govern and direct people in every walk of life, but not be governed by others." As fanciful as this dream might seem, it does appear to be shared by those Muslim Brothers regarded as enlightened.

In the wake of the Arab Spring, Rachid Ghannouchi, the exiled leader of the Muslim Brotherhood in Tunis, returned there from London to help run the country after President Ben Ali was ousted. In the Islamic world Ghannouchi is regarded as one its foremost scholars. Last year, Time magazine included him among the world's 100 most influential people and he was presented with the Chatham House Prize by the Duke of York for promoting "a culture of tolerance and bridge-building" with minority secular parties in the new Tunis.

Yet Ghannouchi has also spoken of his hopes for what he calls the "Islamic project" and the "rebirth of a civilisation" which is "qualitative and humane rather than quantitative and secular". And what has prevented the rebirth of civilisation?

"Zionism," according to Ghannouchi. Zionism "represents a secular onslaught on the heart of our Islamic nation" (i.e. Palestine), which he has portrayed as a sort of virus spreading "octopus-like over the whole planet, embracing and transforming every aspect of existence by means of its economics, communications, arts, and literature, or — more crudely — through the presence of its fleets, intelligence agencies, and the recruitment of local converts . . .", and thereby repressing "hope for a global liberation".

Zionism, Ghannouchi has written, is "hostile to every element rooted in ethical and religious principles", spreading godlessness, greed and materialism. "The Islamic Project, by contrast, is its polar opposite representing the hope that human civilisation can be rescued from this new worship of the golden calf."

It's hard to believe that such an admired scholar and leader would have wished to conjure up a 21st-century echo of the Protocols of the Elders of Zion, the notorious early-20th-century anti-Semitic fraud. And yet some leading Muslim Brothers clearly still do believe in the authenticity of the Protocols. Listening to one of Qaradawi's fatwa council meetings in Watford in 2004, Steven Merley nearly fell off his stool when he discovered that the Protocols had been introduced in the proceedings as a serious reference source.

This is no aberration. In 2009, Sheikh Qaradawi thanked Hitler for having "managed to put Jews in their place . . . Allah willing, the next time will be at the hand of the (Muslim) believers."

Ghannouchi has served alongside Qaradawi as a member of both his European Council for Fatwa and Research and his International Union of Muslim Scholars. They and leaders of the designated terrorist group Hamas were also joint signatories to a 2004 jihadi declaration in support of Iraqi fighters attacking UK and US forces in Iraq — despite the UK having provided Ghannouchi with sanctuary from his oppressors in the former Tunisian regime.

Why, one is left wondering, did the Foreign Office allow Prince Andrew to dignify Chatham House's exaltation of Ghannouchi as an icon of "bridge-building" let alone "tolerance" when Ghannouchi has also worked so closely with a man who thanks Hitler for exterminating six million Jews?

Indeed, why would Ghannouchi himself wish to have anything at all to do with the Brotherhood when, according to Merley, anti-Semitism is core to its ideology? Shortly before becoming Egyptian president, not only did Mohamed Morsi refer to Jews as "apes and pigs", but Merley also discovered that he subscribes to yet another paranoid fantasy: the one about the real 9/11 attackers being as yet "unknown".

So what of the Brotherhood network in Britain? For clues we can turn to the structure we know was established in America in the 1980s by what the FBI has called the "International Muslim Brotherhood". And much of what was strctured there, we know was structured here even earlier.

In the late 1990s, a mass of videos and documents recovered by US law enforcement revealed a tangle of organisations structured like a Russian doll, with one front organisation inside another, inside another and so on. The immediate objective was to strengthen the Brotherhood's Palestinian branch, Hamas, by covertly promoting its goals in America. The focus was to be on the "brutality of the Jews" and religious aspects of the Israel-Palestine conflict, especially Jerusalem. The American investigation led in 2008 to the successful prosecution of four executives of an Islamic charity used as a smokescreen for funding Hamas.

But there was also a longer-term and broader objective. The documents revealed a clear understanding of American culture and political structures and how these could be exploited, to establish what, in essence, was an Islamic beachhead. A memorandum from a US Muslim Brotherhood leader said:

"The Ikhwan [Muslim Brotherhood] must understand that their work in America is a kind of grand Jihad in eliminating and destroying the Western civilisation from within and ‘sabotaging' its miserable house by their hands and the hands of the believers so that it is eliminated and God's religion is made victorious over all other religions."

We may scoff at the sheer audacity of this ambition, but Islamism is not an ideology that can stand still. It has to expand and it plays a long game, as Dr Muzammil Siddiqi, the British university-educated ex-president of the Islamic Society of North America, has explained to American Muslims:

"By participating in a non-Islamic system, one cannot rule by that which Allah has commanded. But things do not change overnight. Changes come through patience, wisdom and hard work. I believe that as Muslims we should participate in the system to safeguard our interests and try to bring gradual change for the right cause, the cause of truth and justice. We must not forget that Allah's rules have to be established in all lands, and all our efforts should lead to that direction."

Have "all the efforts" of the Brotherhood in Britain also been directed towards that goal? In Britain, a strong and influential Brotherhood network has been built up since the 1970s — both south Asian and Arab in origin — with some organisations identical to those uncovered by US law enforcement agencies. It is through these organisations that we see what Steven Merley describes as "mischief making".

As with anti-Semitism, the grievance narrative is core to Brotherhood ideology, and it is one that has been worked up very successfully by inflamed rhetoric since 9/11 over British involvement in Iraq and Afghanistan and over the Israel-Palestine conflict. Apocalyptic language is routinely used. Israel can be criticised for many things, despite the provocation of a near-permanent terrorist threat. But "ethnic cleansing", introducing "apartheid", inflicting "genocide" and even a "holocaust"?

We have seen this grievance narrative relentlessly at work on the Islam Channel, the most popular Islamic satellite TV channel in Britain today, which has given platforms to Brotherhood followers and been fined by the broadcasting regulator Ofcom for bias in breach of the Broadcasting Code after mainstream Muslims complained it had been promoting a fringe and intolerant form of Islam at the expense of mainstream voices, including in its coverage of the Israel-Palestine conflict. Hamas supporters had gone unchallenged, asserting opinion as fact. Today, the channel still feeds the grievance narrative of a global war on Islam by repeating to viewers in programme breaks that it is a "voice for the voiceless" and a "voice for the oppressed". Most recently we have seen the grievance narrative in the Brotherhood's response to Woolwich.

One senior Muslim Brother in Britain today is Mohammed Sawalha, a fugitive Hamas commander described by a Brotherhood website as being "responsible for the political unit of the international Muslim Brotherhood in the UK". Membership of the Brotherhood is not a badge Sawalha wears publicly for members; followers have been generally careful to obscure their radicalism, forever cleaving towards the Muslim and non-Muslim mainstream as "noble" (a word they often use) campaigners for justice and civil rights.

In Britain, the latest of several Brotherhood-aligned umbrella organisations is the "Enough Coalition". It includes the British Muslim Initiative (BMI, of which Sawalha is chairman), Friends of Al-Aqsa, Federation of Students Islamic Societies, London Muslim Centre and the Islamic Forum of Europe in alliance with the hard-left "Stop the War Coalition" and a group run by Ken Livingstone called "One Society Many Cultures". The Enough Coalition condemned Woolwich, only then to call for a public debate about the "effect of Britain's foreign policy" instead of Muslims being "collectively demonised" for the attack. At the same time the BMI tweeted a photograph of Tony Blair taking a picture of himself, smiling in a self-satisfied way superimposed against a raging inferno.

While not excusing Woolwich, this attempt by the Enough Coalition to "explain" the barbarity of the attack as a consequence of Britain's involvement in the 9/11 wars is both mischievous and harmful.

Iraq and Afghanistan were the response to 9/11, not the other way around. Ah yes, goes the counter-argument, but the West was supporting Israeli oppression of Palestinians long before 9/11.

In fact, the decade before 9/11 was one of hope. The Oslo Accords had been signed, and the PLO said it would recognise Israel's right to exist. And what did the Muslim Brotherhood do? Its Palestinian branch, Hamas, did everything it could to destroy Oslo — by building up Hamas's power base with funds to its welfare network, by inflaming the conflict through its portrayal as a religious war rather than a struggle for land, and by popularising suicide bombing. The barbaric legacy was felt in London and Madrid years later. The Brotherhood network in this country, and throughout the West, played its part in snuffing out one of the few glimmers of light that have flickered in the 65 years of Arab-Israeli conflict.

Echoing both Qaradawi, and Ghannouchi, Kamal Helbawi has said that the Israel-Palestine conflict represents far more than just a battle for land: "Oh honoured brothers," he told American Muslims before coming to London, "the Palestinian cause is not a struggle on borders or on land only. Rather, it is an absolute clash of civilisations: a satanic programme led by the Jews and those who support them and a divine programme carried by Hamas and the Islamic Movement in particular and the Islamic peoples in general."

Helbawi is, of course, right, although the "clash" is not one, as he interprets it, between "satanic" Jews against "divinely" inspired Muslims. Rather, the Israel-Palestine conflict has confronted mankind with a test, like no other, about universal values to do with fairness, justice, and above all, evidence-based truth about the cause and conduct of both sides.

The Brotherhood's reaction to the Syrian crisis has exposed a very important truth about what the "Islamic project" to which Sheikh Ghannouchi referred is really about. Sheikh Qaradawi galvanised the global Brotherhood's opposition to the 9/11 wars on the apparently inviolate principle that Muslim majority lands had been invaded, and that violence was justified in removing British and American forces. But just listen to him when it comes to Syria where, with a bit of help from the West, the Muslim Brotherhood — now begging for help from the West — aspires to power.

The Brotherhood's self-same spiritual leader has "implored America . . . to behave like men of honour and intervene in Syria . . . we thank America for the delivery of non-lethal military equipment to Syrian fighters, but this is not enough." Now "direct military aid" is coming. Could it just be that the Brotherhood sees here the chance of inching one more Arab country into the Islamic world order under Sunni Islam?

Anger over foreign policy may be the proximate cause of Woolwich and other atrocities. But for the root cause, we must look elsewhere — though manifestly not to Muslims in general. Look at the faces and listen to the speeches of the vast majority of Muslim leaders in their condemnation of Woolwich. They were heartfelt, devoid of excuses, unlike some post-7/7 responses.

The problem of violent extremism is not "political" requiring "only a political solution" in the shrill words of Asghar Bukhari of the Muslim Public Affairs Committee which claims to be the UK's "leading Muslim civil liberties group". MPACUK may not be part of the Brotherhood but it is an example of how successful the Movement has been in getting other Muslim groups to adopt their narrative.

No, the problem of violent extremism lies with the political and ideological strain injected into Islam by the Muslim Brothers for 85 years — a strain which is not, at its heart, compatible with a pluralistic, open-minded, tolerant, liberal society. Woolwich was the very extreme end of this ideology: a misplaced grievance narrative, cosmic anti-Semitism, and violently inflammatory rhetoric. To deny that this brew cannot possibly be a product of the political variant of Islam (as distinct from its religious one) is not merely complacent. It is also irresponsible.

But here is a question: why are so few fair-minded people in this country not prepared to admit and confront the malign influence that the Muslim Brotherhood has brought here?
Steven Merley has fought a long, lone battle to get people even to acknowledge the existence of a global Brotherhood network. By exhaustive attention to detail, he has patiently built up a picture that ought to worry anyone. Yet the Brotherhood scarcely rates a mention in the most of the media. The centre ground seems to have lost its nerve.

What particularly worries Merley is that extreme right-wing groups here and in America are filling this vacuum. They claim that all Muslims are the problem and that the Koran is at the heart of a Muslim master-world plot. This is as dangerous as it is unjust.

Yet it is precisely this fear of being tarred by a far-right brush that has caused the centre to press the mute button. The Brotherhood and its secular allies on the Left have succeeded in closing down the debate.

Without the Brotherhood's protective "faith" shield there would be no such inhibition to labelling this movement for what it is: a parallel universe, wreathed in paranoia about the intentions of the West, swearing fealty to anti-racism, community cohesion, peace, justice and all the rest, while simultaneously behaving in a way that keeps young Muslims in a permanently febrile state. "Basically, they play games with the facts," says Merley. "And they count on the naiveté of reporters, academics and politicians to push their agenda."

Brotherhood scholars, even the "enlightened" Raschid Ghannouchi, have got it the wrong way round. His "polar opposite" of "human civilisation" is not the West, or "Zionism" for that matter. It is the Brotherhood's version of what he calls the "Islamic Project". Chatham House, Prince Andrew and other well-meaning folk, please take note.